The new material editor is really really cool: easy to use and fluid, very nice GUI.
There are 2 points though that are quite annoying in a day to day use:
The fact that for every modification of the graph the preview is not directly showing the change: it goes through a “checker temp material” before displaying the result.
This is very problematic to see the changes and to compare with the material before the modification.
Would ti be possible to recompute the shader in the background and to refresh the preview only when it is ready? During that time a small waiting icon (the three points used all over the editor) could be displayed at the bottom of the preview to inform the user that a change is being done.
The color of the connections gets greyed when we want to make a new connection. It is okay to change the color during a user manipulation, unfortunately this grey is almost the color of the default Comments area (cf image) and it becomes difficult to see what is already plugged and what it not at a moment whereit is important to see it.